没有发现这个题错在哪里可是执行结果总是出现一个错误，求解错误如下cpp(15) : error C2018: unknown character '0xcb'

#include <iostream>
#include <cmath>               
#include <iomanip>              
using namespace std;
int main( )
{
 double a,b,c;
 cout<<"please enter a,b,c：";
 cin>>a>>b>>c;
 if (a+b>c && b+c>a && c+a>b)
  {                                    
   double s,area;                       
   s=(a+b+c)/2;
   area=sqrt(s*(s-a)*(s-b)*(s-c));
   cout<<setiosflags(ios∷fixed)<<setprecision(4);
   cout<<"area="<<area<<endl;                 
  }                                          
else cout<<"it is not a trilateral!"<<endl;
return 0;
}